Technically there is only one phase unless you account for a solution where you have a pure liquid with something dissolved in it. Unless you count aqueous as a phase which is just dissolved. Since you are in high school the answer you are looking for is one. <span />
Answer: 25.8 g of
will be produced from the decomposition of 73.4 g of
Explanation:
To calculate the moles :

The balanced chemical reaction is:
According to stoichiometry :
2 moles of
produce = 3 moles of 
Thus 0.242 moles of will produce=
of 
Mass of
= 
Thus 25.8 g of
will be produced from the decomposition of 73.4 g of
Because molecules in the air scatter blue light from<span> the sun </span>more than<span> they </span>scatter red light<span>.</span>